Gotta assume the monitor supports 60, going to 30 would be terrible.
60 fps, but the current drivers for both AMD and Nvidia (still in development) make you connect 2 cables and essentially treat it like 2 1920x2160 displays from what I read.
8ms, according to the OP.
8ms is the panel switch rate, not the same as the slow refresh rate of the Lenovo due to the bottleneck in the interconnect with the GPU (4 DVI-channels and 41 Hz refresh, when the panel surly did 60 Hz). It is a massive datarate, especially for a 12 year old system.